Circuit-breaker.



F: W. HARRIS.

CIRCUIT BREAKER.

APPL'iUATlON FILED 1991,1910.

1,1 1 3,335, Patented 00t.13,1914

SHBETS SHEET 1.

A 1 v ATTORNEY WITNESSES: VENTOR 60w? BY P. w. HARRIS.

CIRCUIT BEEAKER.

APPLICATION FILED AUG. 6, 1910.

1,1 13,335. v Patented 001;. 13, 1914.

2 BHEBTS*SHEET 2.

v v IYINVENTOB BY 7 A I ATTORNEY FORD w. imnmsfonwmmnsnmie,-PENNSYLVANIA, ASSIGNOR 'ro WESTINGHOUSE- ELEc'rmoANn MANUFACTURINGcoMrA A CORPORATION or PENNSYLVANIA.

To all whom itmay concern):- w I Be it known that I, Form "V HARRIS, acitizen of the United States, and a resident of \Vilkinsburg, inrthecountyof Allegheny and State of Pennsylvania,have invented a new anduseful Improvement in Circuit- Breakers, tof which the following isespecification. Q My intention relates toautomatit circuit breakers, andit has for its object to provide a": simple" fund reliable:calibrationde\iice whereby a'eircuibbrea'ker may be-adjusted 'tointerrupt the circuit. under predetermined -conditions. I Figure 1 ofthe accompanying drawings is. a side elevation of a eirc uit breakerwhich embodiesmy invention; a portion being broken away. Fig. 2 isa"front' View. of a portion.of the mechanism shown in Fig.1,

and-'1 ig. 3' is a sectional view, on the line III-CHI of Fi .1.

Referring-Etc the drawings, the circuitbreaker :"comprises an insulatingslab" or panel 1,"stat1onary contact terminals .2 and 3, amovablecontact member 4,111 operat- "ing -Inechanisn1 5, a-release magnet 6, atripping mechanism 7, and a CallbLfIttlOH device 8.

The stationary cont'actliieniber' 2 comprises a copper block 2*, anauxiliary'copper cont-act -terminal'2", and a carbon arcing contactterminak The contact block2f forms-the-lreadof a terminal stud whichprojects;- through a hole in the i1 sula'ting panel] and-is secured inposition by'a nut 2. f'lhe carimnarcing tip 2. is" fitted securely intoits retaining member 11 which is piyotally mounted-betweenthe sidearms.of

'aii-U-shapeil'bracket fl by-ineans-ofa pin 10,

tact terminal 2" and spring 14 in: position.

The -spring14 is adapted topress againstv tlre iareing t-ip 2 andl'l'laintain'it in engage- -ment',;with its} cooperating arcing tip 2 a"stud f1 8; which forms' the other terminal o'f the breirk'er, The-upperend of the'strap 16 is fa'stened to theirrsulating panel lfby means gofscrews (not shown), a spacing bl 'rcl\" "]9 beinginterposed to providesufii- Specification of Letters Patent. I

Patented Oct. 13, 1914.

- Applicationf led August 6,1910; Serial 1105575399.

'cient room to accommodate the core of the release magnet 6.

j The movable contact member 4 comprises 'an U-shaped casting 22pivoted, at its lower end, on a stud 23, which is mounted in two 'mainsupporting brackets 24 and 25. The free end of theicasting22 is providedwith aspring-supportcd auxiliary contact men1- ber 26 and a similarlyconnected arcing con tact member 27 said contact members beingrespectivelyadapted to cooperate with the stationary contact members 2and 2. .A ma n bridging contact member 28 is com posed of copper stripsheld in position by.

curved clamping blocks 29 and 30, and is pivotally supported in theUshapcd casting 22 by means of a pin 34 and :1 lug 33, the latter beingan integral part of the outer clamping block 30. The contact member,thus supported, is adapted to bridge across {the main stationaryterminals 3 and 2 to establish the coi'mections of the electric circuit.

The completion of the shunt circuit through the auxiliary contactmembers and their resilient supports is'accomplished by ii copper spring36 which is secured to a web 37, cast on the inside of the U-shapedmember 22, and is adapted to engage stationary terminal 3, being bent toconform to the Circular outline of the pivoted end of the movablecontact member.

a The arrangement and proportions of the several contact terminalscomprising the movable contact member 4 are such that, as

the breaker is released, the main contact .member 28, the auxiliarycontact member .2tiand the carbon arcing tip 2'? open sueeessively toconfine the final break and re suiting arc to the carbon art-mg tip.

'The operating mechanism of the breaker comprises an operating lever 40fulcrumed onfa pin 41 between the main su 'ipori'ing brackets 24 and 25,a ckmnecling link 4-1, an

equalizing member 4-3 and a spring -14. The operating, lever 40 isprovided with a retain-- iug pin or catch 47 and a stop 48 to engage thesupporting bracket 2-4, and limit moremeat in a clockwise direction. Theopcrat ing lever 40 is also provided with a. handle 49, at its outerend, and with a spring 50 which'is secured to the operating lever byai'pin filandto a lug 52 on the main supporting bracket. The tension ofthe spring 50 is exerted to collapse the toggle formed by the arm 39 ofthe. operating lever and the connecting Ilink 42, when the latch 54 isreleased.

Equalizing member 43 is contained within the U-shaped casting-22, oneend being .pivotally secured to said casting by a'pin l which islocatedbetween the ends of said member but nearer to its pivoted end.

The release magnet 6 comprises an- U-; shaped core member 61 supportedon bosses 62 and (33 between the main bracket mem hers 24 and 25, amagnetizing coil of a single turn in the form of the copper strap 16,which is located between the arms of said core, and a pivotally mountedarmature (34. The armature-64 is supported upon a shaft (35' andembodies a weighted portion 7 6, and main arms 66 and 66 connected by athin web 67 which is recessed at 68 to accommodate a tripping lever 69.-\Vl1en sufiiciently energized, the armature 64 is attracted by the coremember 61 and makes contact with said core member on its inclined faces72 and 73, the pin 74 serving to maintain a slight air-gap to overcomethe tendency of the core members to stick together. Suflicientweight isplaced. in the lower portion 76 of the armature to insure its separationfrom the core (31 when the magnetizing .force is discontinued.

The tripping mechanism of the breaker comprises a latch 54, whichengages the retaining pin 47 when the breaker is closed, a trippingmember 80 and the armature (34. The latch 54 is pivoted on a pin 81,which projects through extensions 82 and 83 of the main supportingbrackets 24 and 25. order to limit the movement of the latch 54, a pin84 is located in a slot 85 which is provide:-[ at the inner end of thelatch, and this pin also serves as a stop for a spring 86, whichprojects beneath the latch 54 .and maintains it in its normal position.The upper portion of the bent tripping member 80 has arms 88 and 89,said arms being provided with downward extensions 90 and 91, whichstraddle the latch 54 and through which-said member is pivotallysupported by the pin 81. The outer end of the member 80 forms a trigger93 which is provided with an adjustable screw 94 to engage the latch 54.At the inner end of the tripping mem-' her, the two arms 88 and 89 mergeinto a single rod 69, and shoulders 99 and 100 are provided to engagethe web 67 of the magnet 65 armaturoas said armature is attracted tocore. The lower portion of the rod 69 forms a button 104 which isreadily accessible through an opening 105 in the bottom plate 106 of thebreaker frame.

The calibration device comprises an in clined plate 108 which isadjustably secured to the main arms 66 and 66 of the armature .64 bymeans of slots 110 and 111 and screws 112' and 113, a rotatable member117 pinned to a shaft and provided with one convolution of a helix 120of great pitch, the axis of the helical member and the edge of the platebeing in the same plane, but at anan le to each other, cylindricalcalibrated disi 118 provided with an opening or win dow 121 in the frontplate 122 of thebreaker frame, and an adjusting knob 119.

The calibration plate 108 rests upon the periphery of the helix 120, andthe position of the point of contact between said plate and helix isvaried by the adjusting knob 119. It will be readily understood that, asthe helix is turned by right-hand rotation of the adjusting knob, thepoint of contact between the plate and the helix travels to the left,thus raising the plate and consequently effecting a decrease in thelength of the air-gap between the armature 64 and the core member 61. Bythus varying the point of contact, the length of air-gap may be adjustedto correspond to any predetermined current value desired, within therange ofadjustment obtainable. The angle of inclination of thecalibration plate is the controlling feature which determines themaximum and minimum current adjustments which may be secured for a givensetting of the plate. If the angle between the- .is at its extreme leftposition. The setting of the left end of the plate is then adjusteduntil actual test trips the breaker at two hundred amperes. The pointof'contact is then changed to its extreme rightposition and the rightend of theplat/e is ad'usted until the breaker trips at one tho tremesettings determined, intermediate ad-.

justrhents are secured by varying thepoint of contact alongtheplate bymeans ,of the adjusting knob. -Havingonce set the plate for a particularrange .of adjustmehts, the calibration disk 118 is raduatedcorrespondingly mamperesso. t at, to adjust the ami Y peres on actualtest. With the two exbreaker to trip at any predetermined amount ofcurrent traversing the circuit, it is only necessary to turn theadjusting knob until the required figure on the disk is seen through thewindow 12].- opposite the arrow 123.

The operation of the breaker is as follows: Assuming that the breaker isclosed, the various parts occupying the positions shown in the drawings,the breaker may be released either manually or automatically. In orderto trip the breaker by the hand of the operator, it is only necessary toinsert a finger through the opening 105 and press upward upon thetripping rod 69 to cause the trigger 03 to release the latch 54 by meansof the adjusting screw 94, whereupon the springs 50 and H act inconjunction to collapse the toggle formed by the operating lever 40 andthe connecting link 4:3, and cause the- .to its dead center and,consequently, exerting a considerable pressure upon the equalizingmember 43 which closes the contact members. The breaker is held in itsclosed position by means of the latch 5i,'\vhich engages the retainingpin 47 when the opcrat-inghandle is in its lowest position.

'hile I have described and illustrated a specific structure, I desirethat variation in size and arrangement ofparts may be effected which donot depart from the spirit and scope of my invention, and I furtherdesire that only such limitations shall be imposed as are indicated inthe appended claims.

I claim as my invention:

-1. The combination with a magnetizable core comprising a stationaryportion and a movable portion, and a magnetizingcoil for said core, of arotatable member provided with one convolution of a helical thread ofgreat pitch, and a supporting plate adjustably secured to the movablecore member and adapted to rest upon the periphery of the helicalthread, the edge of the plate and the axis of said helical member beingin the same plane but non-parallel. i

2. The combination with a magnetizable core comprising a stationaryportion and. a pivotally supported movable portion, and a magnetizingcoil for said core, of a rotatable helical cam and an inclinedplateadjustably secured to the movable core member and adapted to restupon the periphery of the rotatable helical cam, the air-gap between thecore members beingdependent upon the position of the point of contactbetween said inclined plate and said cam helix,

3. In a circuit interrupter, the combination with a stationary core, apivotally mounted movable armature, and a magnetizing coil, of asupporting plate adjustably secured at each end to the free end of themovable armature by means of a screw and slot, of a rotatable helicalcam member upon which the edge of said bearing plate rests, the edge ofthe plate and theaxis of the cam member being in the same planebutnon-parallel.

4. In a circuit interrupter, theco'mbination with a tripping magnetcomprising a stationary core, a magnetizing coil therefor and apivotally supported movable arma ture, of a rotatable helical cammember, and a plate adjustably secured to the free end of said movablearmature and having an inclined edge to be engaged by said cam member.

5. The combination with a release magnet for circuit interrupter-scomprising a stationary core, a magnetizing coil-therefo'i' and amovable armature provided with an' attachment having an inclinedsurface, of a helical cam member adapted to engage said inclined surfaceto adjust the interrupter v to trip at any predetermined amount ofcurrent.

In testimony whereof, I have hereunto subscribed my name this 28th dayof July, 100

FORD W. HAR IS.

Witnesses IRENE \VOLFENDALE, B. B. HrNEs.

